# What is CVE-2021-1227?

> CVE-2021-1227 is a high-severity flaw (CVSS 8.1) in NX-OS from Cisco, published on 24 February 2021. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 0.7%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2021-1227

## At a glance

- **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle.
- **Precursor Intelligence risk score:** 47 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 8.1 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 0.7% (latest exploit-likelihood forecast)
- **Published:** 24 February 2021
- **Record last updated:** 3 March 2021
- **Main product:** NX-OS from Cisco
- **Affected products:** 46

## What is CVE-2021-1227? In plain terms

It can be attacked from anywhere on the internet without logging in, but a person has to take an action first. If it works, the attacker can read data and change data.

### The official description

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected system. This vulnerability is due to insufficient CSRF protections for the NX-API on an affected device. An attacker could exploit this vulnerability by persuading a user of the NX-API to follow a malicious link. A successful exploit could allow the attacker to perform arbitrary actions with the privilege level of the affected user. The attacker could view and modify the device configuration. Note: The NX-API feature is disabled by default.

### What kind of flaw is it?

- CWE-352: Cross-Site Request Forgery (CSRF)

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- Does someone have to click: Yes, a person has to take an action
- What an attacker gets: Can read data and change data

Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N`

## Is CVE-2021-1227 being exploited? Not that we know of

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 0.7%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 0.7%, 0.7%, 0.7%, 0.7%, 0.7%, 0.7%, 0.7%.

### Timeline

- 24 February 2021: Published
- 3 March 2021: Record last updated

### How Precursor Intelligence ranks it

CVE-2021-1227 scores **47 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2021-1227?

The published record lists 46 products.

- [NX-OS](https://www.precursorintelligence.com/product/cisco/nx-os) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Operating system): 7.3(8)n1(0.809), 8.4(2a), 8.4(3), 8.4(3)s19, 9.3(3)idi9(0.569)
- [Mds 9148s](https://www.precursorintelligence.com/product/cisco/mds_9148s) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Mds 9250i](https://www.precursorintelligence.com/product/cisco/mds_9250i) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Mds 9706](https://www.precursorintelligence.com/product/cisco/mds_9706) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Mds 9710](https://www.precursorintelligence.com/product/cisco/mds_9710) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3048](https://www.precursorintelligence.com/product/cisco/nexus_3048) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 31108pv-V](https://www.precursorintelligence.com/product/cisco/nexus_31108pv-v) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 31108tc-V](https://www.precursorintelligence.com/product/cisco/nexus_31108tc-v) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 31128pq](https://www.precursorintelligence.com/product/cisco/nexus_31128pq) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3132c-Z](https://www.precursorintelligence.com/product/cisco/nexus_3132c-z) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3132q-V](https://www.precursorintelligence.com/product/cisco/nexus_3132q-v) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3132q-X](https://www.precursorintelligence.com/product/cisco/nexus_3132q-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3132q-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3132q-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3164q](https://www.precursorintelligence.com/product/cisco/nexus_3164q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3172pq](https://www.precursorintelligence.com/product/cisco/nexus_3172pq) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3172pq-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3172pq-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3232c](https://www.precursorintelligence.com/product/cisco/nexus_3232c) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3264c-E](https://www.precursorintelligence.com/product/cisco/nexus_3264c-e) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3264q](https://www.precursorintelligence.com/product/cisco/nexus_3264q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3408-S](https://www.precursorintelligence.com/product/cisco/nexus_3408-s) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 34180yc](https://www.precursorintelligence.com/product/cisco/nexus_34180yc) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3432d-S](https://www.precursorintelligence.com/product/cisco/nexus_3432d-s) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3464c](https://www.precursorintelligence.com/product/cisco/nexus_3464c) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3524-X](https://www.precursorintelligence.com/product/cisco/nexus_3524-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3524-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3524-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3548-X](https://www.precursorintelligence.com/product/cisco/nexus_3548-x) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3548-Xl](https://www.precursorintelligence.com/product/cisco/nexus_3548-xl) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 36180yc-R](https://www.precursorintelligence.com/product/cisco/nexus_36180yc-r) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 3636c-R](https://www.precursorintelligence.com/product/cisco/nexus_3636c-r) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5548p](https://www.precursorintelligence.com/product/cisco/nexus_5548p) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5548up](https://www.precursorintelligence.com/product/cisco/nexus_5548up) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5596t](https://www.precursorintelligence.com/product/cisco/nexus_5596t) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5596up](https://www.precursorintelligence.com/product/cisco/nexus_5596up) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 56128p](https://www.precursorintelligence.com/product/cisco/nexus_56128p) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5624q](https://www.precursorintelligence.com/product/cisco/nexus_5624q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5648q](https://www.precursorintelligence.com/product/cisco/nexus_5648q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5672up](https://www.precursorintelligence.com/product/cisco/nexus_5672up) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5672up-16g](https://www.precursorintelligence.com/product/cisco/nexus_5672up-16g) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 5696q](https://www.precursorintelligence.com/product/cisco/nexus_5696q) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 6001](https://www.precursorintelligence.com/product/cisco/nexus_6001) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 6004](https://www.precursorintelligence.com/product/cisco/nexus_6004) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 7000](https://www.precursorintelligence.com/product/cisco/nexus_7000) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 7700](https://www.precursorintelligence.com/product/cisco/nexus_7700) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 9200](https://www.precursorintelligence.com/product/cisco/nexus_9200) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 9300](https://www.precursorintelligence.com/product/cisco/nexus_9300) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified
- [Nexus 9500](https://www.precursorintelligence.com/product/cisco/nexus_9500) by [Cisco](https://www.precursorintelligence.com/vendors/cisco) (Hardware): version not specified

## How do I fix CVE-2021-1227?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

### References

- [tools.cisco.com](https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-nxapi-csrf-wRMzWL9z) (Vendor advisory)

## Questions

### What is CVE-2021-1227?

CVE-2021-1227 is a high-severity flaw in NX-OS from Cisco, published on 24 February 2021. It can be attacked from anywhere on the internet without logging in, but a person has to take an action first. If it works, the attacker can read data and change data.

### How serious is CVE-2021-1227?

It scores 8.1 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2021-1227 is 47 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

### Is CVE-2021-1227 being exploited?

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 0.7%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2021-1227 affect?

For NX-OS from Cisco: 7.3(8)n1(0.809), 8.4(2a), 8.4(3), 8.4(3)s19, 9.3(3)idi9(0.569). The record lists 46 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2021-1227?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2021-1227 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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